326 DARWimAN-A. 



experiments yielded similar results. Even pollen, 

 which would not rarely be lodged upon these leaves, 

 as it falls from surrounding wind-fertilized plants, also 

 small seeds, excited the same action, and showed signs 

 of being acted upon. "We may therefore conclude," 

 with Mr. Darwin, "that Pinguicula vulgaris, with 

 its small roots, is not only supported to a large extent 

 by the extraordinary number of insects which it habit- 

 ually captures, but likewise draws som^e nourishment 

 from the pollen, leaves, and seeds, of other plants which 

 often adhere to its leaves. It is, therefore, partly a 

 vegetable as well as an animal feeder." 



What is now to be thought of the ordinary glandu- 

 lar hairs which render the surface of many and the 

 most various plants extremely viscid ? Their number 

 is legion. The Chinese primrose of common garden 

 and house culture is no extraordinary instance ; but 

 Mr. Francis Darwin, counting those on a small space 

 measured by the micrometer, estimated them at 65,371 

 to the square inch of foliage, taking in both surfaces 

 of the leaf, or two or three millions on a moderate-sized 

 specimen of this small herb. Glands of this sort were 

 loosely regarded as organs for excretion, without much 

 consideration of the question whether, in vegetable 

 life, there could be any need to excrete, or any advan- 

 tage gained by throwing off such products ; and, while 

 the popular name of catch-fly, given to several com- 

 mon species of Silene^ indicates long familiarity with 

 the fact, probably no one ever imagined that the 

 swarms of small insects which perish upon these sticky 

 surfaces were ever turned to account by the plant. 

 In many such cases, no doubt they perish as uselessly 



